With the advent of the Internet and advancements in electronic commerce, online accounts have become an important part of daily life. Online accounts can facilitate interactions between service providers and users, users can access these accounts from any place at any time, and thus online accounts offer an unsurpassed level of convenience for the users. However, as online accounts have become popular, computer networks are facing new challenges. For example, in the pre-Internet era, physical access to a computer network was necessary for an unauthorized access. These networks often provided a high level of security and isolation against unauthorized access, because maintaining the security of a hosting facility was relatively easy.
However, the Internet has made it possible to access these networks from almost anywhere in the world. As a result, physical access to computer networks is no longer necessary to manipulate or exploit their content. Therefore, new groups of sophisticated criminals, many of whom live outside the jurisdiction of the law enforcement of this country, have become active. Often, these criminals orchestrate attacks on the computer networks of companies, universities, and other institutions, and steal sensitive or valuable information. In many cases, the attackers gain access to the networks by obtaining the usernames and passwords of unsuspecting users. In view of these and other deficiencies, maintaining the security of online accounts has become an important task for administrators of computer networks.